const env = require('./config.js');
const Base64 = require('./Base64.js');
require('./hmac.js');
require('./sha1.js');
const Crypto = require('./crypto.js');

const uploadFile = function(filePath, successCB, errorCB) {
  console.log('上传…');
  wx.showLoading({
    title: '上传中...',
  })
  const aliyunServerURL = env.aliyunServerURL;
  const dirname = env.dirname || "";
  const accessid = env.accessid;
  const policyBase64 = getPolicyBase64();
  const signature = getSignature(policyBase64);

  const aliyunFileKey = dirname + (new Date().getTime()) + filePath.slice(filePath.length - 20);
  console.log('aliyunFileKey=', aliyunFileKey);

  wx.uploadFile({
    url: aliyunServerURL,
    filePath: filePath,
    name: 'file',
    formData: {
      'key': aliyunFileKey,
      'OSSAccessKeyId': accessid,
      'policy': policyBase64,
      'Signature': signature,
      'success_action_status': '200',
    },
    success: function(res) {
      if (res.statusCode != 200) {
        errorCB(new Error('上传错误:' + JSON.stringify(res)))
        return;
      }
      wx.hideLoading();
      console.log('上传成功', res)
      successCB(aliyunServerURL+aliyunFileKey);
    },
    fail: function(err) {
      err.wxaddinfo = aliyunServerURL;
      errorCB(err);
      wx.showToast({
        title: '上传失败',
      })
    },
  })
}

const getPolicyBase64 = function() {
  let date = new Date();
  date.setHours(date.getHours() + env.timeout);
  let srcT = date.toISOString();
  const policyText = {
    "expiration": srcT, //设置该Policy的失效时间，超过这个失效时间之后，就没有办法通过这个policy上传文件了 指定了Post请求必须发生在2020年01月01日12点之前("2020-01-01T12:00:00.000Z")。
    "conditions": [
      ["content-length-range", 0, 20 * 1024 * 1024] // 设置上传文件的大小限制,1048576000=1000mb
    ]
  };

  const policyBase64 = Base64.encode(JSON.stringify(policyText));
  return policyBase64;
}

const getSignature = function(policyBase64) {
  const accesskey = env.accesskey;

  const bytes = Crypto.HMAC(Crypto.SHA1, policyBase64, accesskey, {
    asBytes: true
  });
  const signature = Crypto.util.bytesToBase64(bytes);

  return signature;
}

module.exports = uploadFile;